<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Title</title>
</head>
<body>

</body>
<script>
	{
		let a = 1;
		{
			let a = 2;
			{
				let a = 3;
				{
					a = 4;
					console.log(a);
				}
				console.log(a);
			}
		}
	}
</script>
</html>